I vaguely remember in one of the stories dealing with the construction that New Avalon was designed specifically to look like it was old-fashioned, while having none of the failings. Which is why there are empty factory buildings that never housed factories and the like on the surface, while there's top-notch waste management, lots of road and parking space, really efficient disaster management, and a network of rapid deployment defense tunnels underneath. By a person who grew up in and loved the smallish town parts of it are made to resemble.

Feel free to correct me if I'm wrong, but that seems to be the primary design aesthetic.